Rolling element bearings are well known mechanical components which are used to e.g. support a rotating shaft or the like. There exist numerous types of rolling bearings, such as radial rolling bearings which are used to mainly support radial loads, axial rolling bearings which are used to mainly support axial loads, and also rolling bearings which are used to support a combination of radial and axial loads. The bearings may also be provided with seals to seal off the space in which the rolling elements are located. A sealed rolling bearing will be able to prevent dirt, debris etc. from entering the bearing and also the seals may be used to accommodate a lubricant in the bearing. The lubricant may e.g. be oil or grease.
Furthermore, in some occasions, there is a need to equip the bearings with certain functionalities that requires electrical power. For example, the bearings may be equipped with electronic sensors to sense a condition of the bearing, such as vibration, temperature, speed etc. In addition, there may be a need to e.g. equip the bearing with wireless transmitters/receivers, lubrication systems etc., which also would require electrical power. Electrical power can be provided from an external source, a battery etc., but it could also be generated by making use of the rotational energy from the bearing.